Leaf Concentration Practice

From Narutopedia

Leaf Concentration Practice (Unnamed)
Debut
Manga	Chapter #154
Anime	Naruto Episode #88
Data
Classification	General skill

The training method is done by placing a leaf over an individual's forehead and having them direct all their chakra onto the leaf, using it as a focal point.

This exercise can be used by Konoha Academy teachers as a way to teach students how to control their chakra more effectively. However, the true purpose of the exercise is actually to hone the individual's concentration and to keep their mind from becoming distracted. As explained by Iruka, only those who have worked hard on their ability to concentrate can become excellent shinobi. For generations Leaf ninjas have practiced with this method in order to better their concentration. The leaf emblem on the Konoha headband protector originates from this training.

While trying to master the Rasengan, Naruto thinks back to this lesson, and uses Iruka's advice to complete the 2nd stage of the ninjutsu.